The Studiola Californie (ill. 1) which Picasso painted in 1956, precisely on April 2, follows and precedes several paintings on the same theme. It is naturally the painter's own studio, located in Cannes, in the California neighbourhood, which Picasso occupied since the previous year and where he stayed until 1961. We know that the artist liked to work in the vast living-room in which he put all his material and all the found or given objects which he accumulated according to his legendary habit and which shaped his personal universe. Numerous parcels, often left unopened, formed piles. The crates and the furniture coming from the flat in the rue de la Boétie were put in a space "cluttered" with many canvases, hanging on the wall or just put down on the floor. This cheerful shambles struck all those who entered it and was regularly described by commentators who always marvelled at its particularity. Photographs also frequently benefited from such a space and the pictures taken by Douglas Duncan (ill. 2) , André Villers, Edward Quinn generally draw a fair portrait of this laden universe. As for the painting, endowed with this spirit of profusion, it only shows the essential objects which painters need and which are usually found in their studios: the easel, the paintings hung on the walls, the frames carelessly put down on the floor. Other objects or pieces of furniture are represented and somehow correct the ordinarily severe vision of the place of creation which the artist's studio is. The rounded shapes of the ceiling mouldings, the arabesques of the window woodworks and the Mediterranean vegetation which you can discern through the windows make up the background and endow the space with a particular atmosphere in which life seems to flow in all directions. In The Studio, Picasso enjoyed using supple and vibrant shapes which we can, along with others, consider as being tributes to his friend Matisse who had recently died, and which Yve-Alain Bois, in the Kimbell Art Museum exhibition catalogue, studied in depth 1 . The doors and windows show a strange ballet of syncopated shapes and offer in themselves a stunning spectacle. The space is like striated by the areas of lights and shadows and loses itself in inextricable mazes.
Several other versions, around twenty in total, show us the same saturated space in which sometimes appears a character in whom we can easily recognize Jacqueline, sitting in profile in a rocking-chair whose rounded shapes complete the initial composition. Jacqueline is staring at the space and more particularly at one element of its composition which she cannot distract herself from throughout the different versions. With or without a character, the works take up the theme, common in painting, of the painting within the painting.

But whereas the painting is traditionally the opportunity to expose, the opportunity for the artist to show the richness of the collection which he intends to inventory or the opportunity to show his personal production, here it is the emptiness and the lack of form which we are given to contemplate. In this case, it is a canvas set on an easel which changes its location in the different paintings but most often occupies, especially in the most successfully completed versions, the central location. This element is thus highly visible within Picasso's very laden compositions on the theme of the studio, and all the more so as the canvas is blank and that its whiteness pierces space in a particularly dazzling manner. The white rectangle which the artist repeats from canvas to canvas is not an insignificant element as it constitutes a kind of break in the saturated universe we are generally given to see.

In fact, many works which were painted before or after, are similarly marked by this unexpected monochromy which undoubtedly draws the eye because of its brightness. Such is the case for the paintings on the theme of the studio. Canvases, linocuts and drawings show the importance given by the artist to what is likely to be more than a simple detail coming from a random organisation of space. The white and immaculate surface of a painting, generally set in the centre, is indeed recurring in many other works. The painter at work, with or without a model, the painter's own children with or without their mother and a few other examples also belonging to a series are also marked by this neutral and white reserve, a kind of "retinal silence" in the usual chromatic intensity. It seems to be a persistent sign, to be found in all the work, but which undeniably becomes more pronounced during certain periods. We could be tempted to link the affirmed presence of this immaterial mark with biographical elements.
We would maybe discover that it echoes difficult moments in the artist's life, his marital problems and other family or professional relationships. We could maybe expose an even more secret cause that a psychological study could help us identify. But, without denying the relevance of such approaches, we prefer the formal and aesthetic option which the artist himself invites us to take. The problem of the blank canvas was perceived by the painter who mentions it several times. Some of the comments gathered by Marie-Laure Bernadac and Androula Michael give an interesting orientation of analysis. This is the case of the following quotation dating from the very year when he painted The Studio:

"A painting does not exist, it cannot be a mere material object (...) The collector who buys it does not buy an object. He buys something intangible, and one fine day he wakes up with only a frame around an invisible space 2 . ”

One could not express more truly and more precisely the problem raised by this stretch of empty and immaterial painting which the terms intangible and invisible used by Picasso radically qualify as the very space of the whole painting. The painting surface, the appropriation strategies chosen by the painter and the inherent risks he immediately takes, the aporia created by each gesture aiming at filling the void are elements taken into consideration by Pablo Picasso who, in simple but highly pertinent words, raises the crucial problem of the way we look at a painting.

“ The painter himself, he told Daniel-Henry Kahnweiler, does not see anything. He only looks at his painting. There are painters like that, who only look at their painting and who do not see anything 3 ”.

The relationship between the work and the exercise of looking will reveal itself to be a major problem for Picasso, who as he did not ignore his legendary prolixity, is careful, as if to protect himself, to recommend moderation:

“ There are so many realities that if we try to make them all visible, we end up in darkness. (...) There is a moment when we have to stop(...). If not, in the end there would be nothing left 4 . ”
In view of these declarations, the kinds of reserve we highlighted take on a new meaning and allow for a somewhat different reading of the work. Its undeniably profuse character finds in the figuration of the blank canvas a kind of counterpoint which comes to temper the rest of the space, as if to wash it from its excesses. The white canvas, untouched by the brush tip, not loaded with colour or matter, is indeed this Tabula rasa discussed by Daniel Arasse, in a recent text, precisely entitled "On n'y voit rien" (We see nothing). Following John Moffitt and Vicente Carducho, Arasse evokes its fundamental function, that of containing "the all-mightiness of the painter's act, of painting 5 . ” The blank canvas, empty of all sign except that which maybe inscribes itself in its own vacuity, has always puzzled the creators and the art historians. It charms Wassily Kandisky who sees in it undeniable capacities of marvelling and who, through a metaphor, identifies the object and starts to analyse it:

“ Like a pure and chaste virgin with a clear look, with celestial joy, this pure canvas which is also itself as beautiful as a painting 6 . ”

It gives mixed feelings to many other artists, among which dominates the fascination it provokes, which the art historians and historians of colour have highlighted.
In Las Meninas by Velázquez, the blank canvas is, as Daniel Arasse also showed very well, the back side of the painting whose worked surface, the obverse, remains inaccessible to our look. It is probably this visual dilemma which fascinated Pablo Picasso, as evidenced by the many variations he painted around the famous painting in the Prado. As before, it is for the artist the opportunity to take up the problematic of the empty canvas, of the white square or rectangle which contains or waits for the act of painting. But two other elements which are present in the painting by Velázquez have surely held his attention. It is the opening in which the character is profiled, looking at the scene, and the famous mirror in which appears the off-camera image of the royal couple. The presence of the mirror is far from being rare in Picasso's work. Even a brief study of the question shows the importance of the theme.
The early works, the paintings from the beginnings of the century, and of course especially those which deal with body care (such as the unforgettable painting entitled La Coiffure from 1905), the ones which will follow soon with feminine nudes or objects which by tradition belong to the universe of vanity. In the first category of works can also enter the very famous painting Les Demoiselles d'Avignon, if, as some authors suggested, one accepts to see in the central part of the background, the representation of a big mirror. The mirror is a common element in brothels, generally used to exercise an erotic look. Here, through the cubist treatment imposed by the painter, it is utterly inefficient to render the image of the present women's bodies. The eye thus collides with a blind mirror in this painting. What could be considered, during the whole Cubist period, as the consequence of a specifically plastic procedure, becomes a lot more explicit in many subsequent creations. Thus, Large Nude in a Red Armchair (ill. 3) from 1929, shows a rather large mirror whose grey surface, surrounded by its bright yellow frame, does not let us guess anything of the terrible contortions of the seated body. With its impassive surface whose neutral monochromy confounds itself with that of a possible abstract painting, the mirror does not reflect any image and only retains on its surface the insistent reflection of the void. Other works, as famous or less famous, give the same uncertain role to the mirror. They integrate in their composition a unique patch of colour which is striking, not because it reduplicates the image it is supposed to reflect but on the contrary because it dissolves it in the thickness of its "in-significance". The Nude with Bouquet of Irises and Mirror (ill. 4) from 1934, repeats the same device as before, which also appears frequently in anterior and posterior works. The Studio (ill. 5) from 1928, the Still Life from 1936, The Still Life with Candlestick from the following year, the Still Life with Candle, Palette and Red Minotaur's Head, The Still Life with Guitar from 1942, and other works painted during the war, like Coffee Pot and Candle (ill. 6) and Still Life with Candle, both from 1944, all present with more or less emphasis the same rectangular shape whose interior is emptied of all explicit content.
The mirror hung on the wall or put down on the table does not prolong the perspective nor does it reverse the data as it usually does. It does not open onto anything and leaves no opportunity for the imagination to exert itself to fill in the frustration. It is a surface devoid of all specular function, a hollowing-out which is not endowed with any auratic function. It does not inscribe itself in the represented space as the attribute of the Imitatio sapiens whose history Daniel Arasse recently retraced 7and it even less fulfils its usual function, that of denouncing, via the comput digitalis, human vanity and pride. It rather seems to be a painting lesson in itself which raises the question of the limits of any representation.
The part it plays here is to be put in parallel with that given to the window.
The window is also deprived of its traditional mission, that, according to the Albertian lesson, of being a symbol of opening onto the exterior world, as in Picasso's paintings it does not offer any perspective of the kind. Most of the paintings in which it appears only show its frame. A simple rectangular monochrome or to use Michel Foucault's expression in The Order of Things "pure opening" which like the mirror or the blank canvas seen before, does not distract the look nor diverts it from its object. No still life or character figuring in front of the window is prisoner of an illustrated perspective. Each element is on the contrary radically confronted with a circumscribed space which can be apprehended as a reserve within the painting, as a kind of neutral and distant zone which fully returns to the word its semantic polyvalence. This kind of white screen receives and underlines the impassibility of Paul as a Pierrot (ill. 7) from 1925 as well as that of The Sculptress from 1924-1925. But the blank rectangle of the window can also receive the dislocated bodies of The Dance (ill. 8) from 1925, the languid body of daydreaming Marie-Thérèse or the body of one of Guernica's women, shattered by pain. Even hidden by the requirements of the imposed curfew, the window does not present itself in any other way, in the war paintings, than as a simple network of plain strips which undoes the perspectivist endeavour and severely surrounds, through the uprights of its frame, the subject of the painting itself.
Bull's Head from 1942 or Still Life with Bull's Head (ill. 9) from the same year are, in that respect, particularly striking. The composition takes up the same device and accentuates it, so that the animal's head is in a way at the heart of an orthogonal structure, which even though it is a window, could easily be read as the frame of the canvas.

This white or neutral surface sometimes appears as completely autonomous in Picasso's works. Its presence abstracts itself from any figurative support and shows itself without resorting to any object. The reserve, a part devoid of any matter as in Portrait of a Painter (after El Greco) from 1950 or partly covered with a layer of painting as in Harlequin (ill. 10) from 1915,the "window" thus opened by Picasso is another way to compensate, through the void, the profusion of pictorial signs. Unless it integrates itself, as in the Lying Woman from June 1946 or in the remarkable series of nudes on plywood painted in Antibes during the autumn of the same year, as an element of complementary plasticity.

This reserve, which as we have seen can take the form of the white canvas, of the blind mirror or of the empty window, elements sometimes gathered within a single canvas as in The Shadow (ill. 11) on the woman of December 1953, whose recurrence throughout Picasso's work we have attempted to show, raises a real and interesting questioning in that it appears in other images or documents whose topic is the artist itself.

A photograph by André Villers shows Picasso in the embrasure of a French window (ill. 12), another photo by Edward Quinn (ill. 13) makes him appear in front of a blank canvas, a third picture also by Villers shows us the artist, also wearing a mask, in front of a mirror. These three photographs, beyond their status of works of art, can be used as documents and help our argumentation. They form a kind of trilogy which not only replies very precisely to the figures of the reserve we put forward but can also constitute a key to the raised problematic. In the three photographs, the frontal pose of the artist is striking. The face-to-face which takes place between the artist and the onlooker in front of the reserve in the background is indeed largely perceptible and seems over-highlighted in another photograph, taken by David Douglas Duncan (ill. 14). It is within the context of bullfighting, an important theme for Picasso, and under the appearance of a muleta, or more prosaically, of a simple piece of cloth, that the painter's white canvass reappears. The white canvas, beyond the silence it conveys, can be a tool of optical fascination in which the look comes to bump, an object of diversion of a force which is going to exert itself or an element of reception of another in the making and contains all the possibilities. The artist's signature which ostensibly and largely strikes the surface of one of the canvases, laid in the half-light on its easel, seems to provide an irrefutable piece of evidence.